From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:45692)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1bmKGw-0007iJ-KY
	for qemu-devel@nongnu.org; Tue, 20 Sep 2016 08:35:42 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1bmKGr-0003DB-BN
	for qemu-devel@nongnu.org; Tue, 20 Sep 2016 08:35:37 -0400
Received: from mx1.redhat.com ([209.132.183.28]:44828)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1bmKGr-0003C6-5P
	for qemu-devel@nongnu.org; Tue, 20 Sep 2016 08:35:33 -0400
References: <20160920123126.5400.29283.stgit@PASHA-ISP.def.inno>
	<20160920123138.5400.67174.stgit@PASHA-ISP.def.inno>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <8ebdaf52-f7f9-c6ac-3a85-3149b2e55346@redhat.com>
Date: Tue, 20 Sep 2016 14:35:28 +0200
MIME-Version: 1.0
In-Reply-To: <20160920123138.5400.67174.stgit@PASHA-ISP.def.inno>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH v3 2/8] block: set snapshot option for
 block devices in blkreplay module
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>, qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, jasowang@redhat.com, quintela@redhat.com, mst@redhat.com



On 20/09/2016 14:31, Pavel Dovgalyuk wrote:
>      /* Open the image file */
>      bs->file = bdrv_open_child(NULL, options, "image",
> @@ -40,6 +112,43 @@ static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags,
>          goto fail;
>      }
>  
> +    opts = qemu_opts_create(&blkreplay_runtime_opts, NULL, 0, &error_abort);
> +    qemu_opts_absorb_qdict(opts, options, &local_err);
> +    if (local_err) {
> +        ret = -EINVAL;
> +        goto fail;
> +    }
> +
> +    /* Prepare options QDict for the overlay file */
> +    qdict_put(snapshot_options, "file.driver",
> +              qstring_from_str("file"));
> +    qdict_put(snapshot_options, "driver",
> +              qstring_from_str("qcow2"));
> +
> +    snapshot = qemu_opt_get(opts, "overlay");
> +    if (snapshot) {
> +        qdict_put(snapshot_options, "file.filename",
> +                  qstring_from_str(snapshot));
> +    } else {
> +        char tmp_filename[PATH_MAX + 1];
> +        ret = get_tmp_filename(tmp_filename, PATH_MAX + 1);
> +        if (ret < 0) {
> +            error_setg_errno(errp, -ret, "Could not get temporary filename");
> +            goto fail;
> +        }

No, this is unnecessary.  The image is unused in this case, so you can
specify the overlay as image=foo.qcow2.


Paolo